<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>选择器</title>
    <style type="text/css">
        /*标签选择器*/
        p{
            color: red;
        }
        /*id选择器*/
        #box{
            color: blue;
        }

        #box1{
            color: yellow;
        }
        /*类选择器*/
        .t1{
           font-size: 50px; 
        }
        /*群组选择器*/
        #box,.t1,a{
            background: green;
        }
        /*后代选择器*/
        html body .t1 span{
            font-size: 30px;
        }
        /*通用选择器*/
        *{
            font-family: "宋体";
        }
        
        /*伪类选择器*/
        p:hover{
            color: green;
        }


    </style>
</head>
<body>
    <p>学并思1</p>
    <p id="box">学并思2</p>
    <p id="box1">学并思3</p>
    <p class="t1">学并思4</p>
    <p class="t1">
        <span>学并思5</span>
    </p>
    <p class="t1">学并思6</p>
    <a href="">学并思</a> 
    <span>学并思7</span>
    <!-- ul.box>li.itme*10>a.link>{aa}   -->
    <a href="" class="header_link"></a>
</body>
</html>